BMR Calculator

The Basal Metabolic Rate (BMR) Calculator estimates the energy your body uses at rest in a neutrally temperate environment, in a post-absorptive state (~12 hours fasting).

Modify the values below and see your BMR and daily calorie needs instantly.

Your Information

Your BMR & Daily Calorie Needs

Your Basal Metabolic Rate
1,650
Calories/day
Sedentary
1,980
Little or no exercise
Light Activity
2,269
Exercise 1-3 times/week
Moderate Activity
2,558
Exercise 4-5 times/week
Active
2,846
Daily or intense exercise 3-4 times/week
Very Active
3,135
Intense exercise 6-7 times/week
Extra Active
3,300
Very intense exercise daily or physical job
Exercise Intensity Guide
Exercise: 15-30 min elevated heart rate
Intense: 45-120 min elevated heart rate
Very Intense: 2+ hours elevated heart rate

Understanding Your BMR

What is BMR?

Basal Metabolic Rate (BMR) is the number of calories your body needs to perform basic life-sustaining functions while at rest. This includes breathing, circulation, cell production, and nutrient processing. Your BMR represents about 60-75% of your total daily energy expenditure.

Why BMR Matters

Understanding your BMR is crucial for weight management and fitness goals. It provides a baseline for determining your daily caloric needs. To lose weight, consume fewer calories than your total daily expenditure. To gain muscle, consume more. Your BMR helps you set realistic, science-based nutrition targets.

Activity Level Impact

Your total daily calorie needs depend on your activity level. The activity multipliers account for exercise and daily movement beyond your BMR. Be honest about your activity level—overestimating can lead to consuming too many calories, while underestimating may leave you under-fueled for your workouts.

Formula Differences

Mifflin St Jeor: Most accurate for general population, considers age, gender, height, and weight.

Harris-Benedict: Classic formula, slightly less accurate but widely used.

Katch-McArdle: Most accurate for lean individuals, requires body fat percentage, focuses on lean body mass.

Using Your Results

Use your BMR and activity-adjusted calories as a starting point. Track your weight and energy levels for 2-3 weeks, then adjust as needed. For fat loss, aim for a 300-500 calorie deficit. For muscle gain, aim for a 200-400 calorie surplus. Always prioritize nutrient-dense whole foods and adequate protein.

Important Considerations

BMR calculations are estimates. Individual metabolism varies based on genetics, muscle mass, hormones, and health conditions. Never eat below your BMR for extended periods—this can slow metabolism and harm health. Consult a healthcare professional or registered dietitian for personalized nutrition advice.